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Preferred IUPAC name
Other names
2,4-Dinitrophenyl chloride
3D model (JSmol)
Abbreviations CDNB; DNCB
ECHA InfoCard 100.002.321
EC Number 202-551-4
Molar mass 202.55 g·mol−1
Appearance yellow crystals
Odor almond-like
Density 1.6867 g/cm3
Melting point 54 °C (129 °F; 327 K)
Boiling point 315 °C (599 °F; 588 K)
Solubility soluble in ether, benzene, CS2
1.5857 (60 °C)
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oilHealth code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gasReactivity code 4: Readily capable of detonation or explosive decomposition at normal temperatures and pressures. E.g., nitroglycerinSpecial hazards (white): no codeNFPA 704 four-colored diamond
Explosive limits 2–22%
Lethal dose or concentration (LD, LC):
1.07 g/kg (rat, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

2,4-Dinitrochlorobenzene (DNCB) is an organic compound with the formula (O2N)2C6H3Cl. It is a yellow solid that is soluble in organic solvents. It is an important intermediate for the industrial production of other compounds.[2]

DNCB is produced commercially by the nitration of p-nitrochlorobenzene with a mixture of nitric and sulfuric acids. Other methods afford the compound less efficiently include the chlorination of dinitrobenzene, nitration of o-nitrochlorobenzene and the dinitration of chlorobenzene.


By virtue of the two nitro groups, the chloride is susceptible to nucleophilic substitution. In this way, the compound is a precursor to many other compounds. Base gives the dinitrophenol, ammonia the dinitroaniline, methoxide the dinitroanisole, and amines the secondary amines.

Laboratory use[edit]

DNCB is used as a substrate in GST enzyme activity assays.[3] The molecule is conjugated to a single molecule of reduced glutathione which then absorbs at 340 nm. Affinity of CDNB for each class of GST varies and so it is not a good measure of activity for some forms (e.g. GSTT and GSTZ).[citation needed]

Medical use[edit]

DNCB can be used to treat warts with an effective cure rate of 80%.[4] DNCB induces an allergic immune response toward the wart-causing virus.[4]


DNCB induces a type IV hypersensitivity reaction in almost all people exposed to it, so it is used medically to assess the T cell activity in patients. This is a useful diagnostic test for immunocompromised patients. It can also be used to treat warts.[5]

DNCB can cause contact dermatitis.[6]


  1. ^ "1-Chloro-2,4-dinitrobenzene". Sigma-Aldrich. Retrieved 8 September 2014.
  2. ^ Gerald Booth (2007). "Nitro Compounds, Aromatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a17_411.
  3. ^ Habig WH, Pabst MJ, Jakoby WB (1974). "Glutathione S-transferases. The first enzymatic step in mercapturic acid formation". J Biol Chem. 249 (22): 7130–7139. PMID 4436300.
  4. ^ a b "Treating Warts". Harvard Health Publications. Harvard Medical School.
  5. ^ "Treating warts". Harvard Medical School. Archived from the original on 2010-11-03. Retrieved April 2, 2010.
  6. ^ White SI, Friedmann PS, Moss C, Simpson JM (1986). "The effect of altering area of application and dose per unit area on sensitization by DNCB". Br. J. Dermatol. 115 (6): 663–8. doi:10.1111/j.1365-2133.1986.tb06646.x. PMID 3801307.